Food Allergy Testing

If done correctly, skin tests or blood tests are reliable and can assist in ruling in or out food allergy. Some people do test "allergic" to a food (by skin or blood testing) and yet have no symptoms when they eat that food. To confirm test results, you may need a challenge test. This means that you have to eat or drink small portions of a food in increasing amounts over a period of time to see if an allergic reaction occurs. This is usually done under a physician’s supervision.

What foods make me sick?
Some people know exactly what food causes their allergy. They eat peanuts or a product with peanut in it and immediately break out in a rash. Others need a doctor’s help in finding the cause. Occasionally, the symptoms show up many hours after they have eaten the food.

Your allergy treatment will typically begin with a complete medical history. We will ask you about:

The symptoms you have after eating the food

How long after eating the food these symptoms occur

How much of the food you had

How often has the reaction occurred

What type of medical treatment, if any, you had

The medical history will also include questions about your diet, your family's medical history, and your home and living area.

These questions are used to find out what is causing your allergy or making your symptoms worse. Allergy to pollen in the air, such as ragweed pollen, can be the cause of the swelling or itching in your mouth and throat if you eat certain foods like melons.

Can special diets help pinpoint the problem?

A special diet can help pinpoint foods causing allergies. You may be asked to keep a daily food diary. It lists all food you eat and medication you take, along with your symptoms for the day.

If only one or two foods seem to cause allergies, you may try avoiding them. In this diet, you do not eat the suspect food at all for one to two weeks. If the allergic symptoms decrease during that period and flare up when you eat the food again, it is very likely the food causing your allergy.

However, which food you should avoid (and for how long) and when you should eat the food again (if ever) should be decided together in consultation with your doctor. You should never try to eat even a small quantity of any food you and your doctor have decided against.